#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for(int i = 0; i < n; i++)

int main() {
    string s;
    cin >> s;
    REP(i, s.length()) {
        if (islower(s[i])) {
            s[i] = toupper(s[i]);
        } else {
            s[i] = tolower(s[i]);
        }
    }
    cout << s << endl;
    return 0;
}